Controlled adhesion sterile package seal

ABSTRACT

Controlled-adhesion seal for a sterile package utilizing herringbone half-scores and ink-printed adhesive areas bounded on all sides by unprinted adhesive areas, both to promote proper delamination of the paperboard package along the tear strip during opening and insure impermeability to bacteria while sealed.

United States Patent Cecil et al. Nov. 20, 1973 CONTROLLED ADHESION STERILE 2,745,592 5/1956 Steck 229 51 WB PACKAGE SEAL 2,897,087 7/1959 Lawlor 229/51 TS 3,620,439 11 1971 Morse et a! 206/632 R Inventors: Howard F. Ceeil, Los Angeles;

James L. Armentrout, Huntington Beach, both of Calif.

Southwest Forest Industries, Inc., Phoenix, Ariz.

Filed: July 30, 1971 Appl. No.: 167,625

Assignee:

References Cited UNITED STATES PATENTS 3/1970 Kuster 206/632 R Primary Examiner-William T. Dixson, Jr. Assistant Examiner-Stephen Marcus Attorney-Paul E. Harris et a1.

[57] ABSTRACT Controlled-adhesion seal for a sterile package utilizing herringbone half-scores and ink-printed adhesive areas bounded on all sides by unprinted adhesive areas, both to promote proper delamination of the paperboard package along the tear strip during opening and insure impermeability to bacteria while sealed.

3 Claims, 7 Drawing Figures PAIENIEDnuv 20 ms I James L.Armentrc1ut Howard F. Cecil IN VE N TURS A TTORNEY CONTROLLED ADI-IESION STERILE PACKAGE SEAL BACKGROUND OF THE INVENTION 1. Field of the Invention Sterile medical packaging.

2. Description of the Prior Art Medical devices, surgical instruments and other products used in hospitals must be enclosed in packages which are impervious to bacteria. These packages must also be permeable to gas or steam in order to sterilize the articles contained within the packages. These packages must also be designed with a sterile opening through which the sterilized articles may be withdrawn from the package. As the article is withdrawn through the opening, contact with the sterile lip of the package opening will not contaminate the article being removed. Generally exemplary of the state of the art are U.S. Pat. Nos. 3,626,096; 3,495,702; and 3,498,448.

A mechanism for creating a sterile lip for the opening of such package is a tear strip incorporated in the package. Sealing the leading edge of the tear strip forming a sterile lip is a problem that has not been completely solved. Improper delamination of the half-scored package adjacent the tear strip has proved to be a difficult problem to solve. The seal for the overlying leading edge of the tear strip must adhere to the underlying portion of the package strongly enough to prevent the- SUMMARY OF THE INVENTION The invention is a controlled-adhesion seal forming a bacterial barrier between the leading edge of the tear strip and that portion of the package underlying that leading edge. Th controlled-adhesion seal may include ink-printed adhesive areas bounded on all sides thereof by unprinted adhesive areas. Certain embodiments include' half-scores cut into the paperboard surfaces of the interior of the leading edge of the tear strip or the exterior surface of the trailing edge of the tear strip.

Adhesion of the leading edge of the tear strip to the underlying paperboard may be controlled by varying the ratio of printed adhesive area to unprinted adhesive area in the seal. The greater the ink-printed adhesive layer, the weaker the strength of the seal. The unprinted rivers or continuous areas of unprinted adhesive completely surrounding the adhesive areas insure sterility of the seal. No bacteria can pass this continuous unprinted adhesive area into the package.

The half-cut scores, and in the preferred embodiment, herringbone cross-cut scores, allow similar controlled adhesion of the seal to the underlying package surface. The glue or other adhesive, of a proper viscosity, performs two functions. Where the adhesive of the manufacturers glue line tranverses the half-cut scores and herringbone cross-cut scores, it will tend to seep down into the half-cut scores and herringbone crosscut scores and form a bacterial barrier. The glue in these areas will promote delamination on a selective basis during opening of the package, thus allowing the tear strip to transverse the manufacturers glue line in an ordinary manner without improper delamination occurring.

This inventive concept permits controlled adhesion of the tear strip at its leading edge while preserving the contents of the package bacteria-free prior to opening.

BRIEF DESCRIPTION OF THE DRAWINGS The inventors presently preferred embodiment of the invention is shown in the drawings. In the drawings:

FIG. 1 is a generally isomatric view of a sterile medical package, showing the package in an unopened state.

FIG. 2 is a sectional view of the tear strip taken along line 22 of FIG. 1 and showing the two pairs of halfcut scores which form the tear strip.

FIG. 3 is generally the same cross-sectional view as that of FIG. 2, but showing the tear strip being removed from that portion of the package.

FIG. 4 is a detail view of the leading edge of the tear strip.

FIG. 5 is a detail view of the seal area showing the tear strip lifted from the controlled-adhesion seal and also showing the herringbone half-scores in the trailing edge of the tear strip.

FIG. 6 is a detail view of another embodiment of the weakened seal area with the leading edge of the tear strip lifted, showing the use of herringbone half-scores in conjunction with ink-printed adhesive areas in the seal.

FIG. 7 is a detail view of an embodiment of the weakened seal area with the tear strip lifted, shwing inkprinted adhesive area only in the controlled-adhesion seal.

For the purposes of illustration, only the lower havles of the upper surfaces of trailing edges 14 and the under surfaces of tear strips 12 as seen in FIGS. 5 7 have been shown as being delaminated so that the appearance of these areas before delamination can also be shown in the top halves thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT The inventors preferred embodiment of the invention is shown in FIG. 1 incorporated in a sterile medical package 10. Package 10 includes a tear strip generally designated by the numeral 11. Tear strip 11 includes an overlying leading edge 12, a body portion 13, and an underlying trailing edge 14. (FIGS. 5, 6 and 7) A manufacturers seam 15 is included to bind the two adjacent sides l7, 18 of package 10 to each other. Package 10 is formed from a single sheet of paperboard and includes top 16 and sides 17 and 18. The top and bottom of package 10 may be closed by any suitable means that will form a bacterial barrier, such as by folding and gluing the upper and lower portions thereof. Package 10 is impermeable to bacteria, yet is permeable to a sterilizing medium such as gas or steam.

The adhesive along manufacturers seam 15 must be of sufficient strength to withstand normal shipping and handling, as well as the vacuum and pressure cycles encountered in the various modes of sterilization. The package must withstand these stresses without being torn open or losing its bacteria-free integrity.

Tear strip 11 is formed by two parallel outer halfscores 21 and two inner parallel half-scores 22. As leading edge 12 of tear strip 11 is pulled away from package 10, a plane of delamination 23 is created midway between outer edge 25 and inner edge 26 of package side 17. Delamination plane 23 is therefore an inner plane of side 17 which has not been exposed to bacteria, but has been exposed to the sterilizing medium for package and its contents. Delamination plane is therefore sterile and forms a sterile lip through which sterilized objects can be removed from package 10 without comtamination.

The seal binding leading edge 12 to trailing edge 14 of tear strip 11 is formed by the glue of manufacturers seam 15 between the adhered sides 17 and 18 of package 10. The controlled adhesion seal for the tear strip 11 is formed by alteration of the inner surface of leading edge 12 or the outer surface of trailing edge 14, both of which contact the adhesive of manufacturers seam 15. Controlled-adhesion is defined for the purpose of describing the invention as a weakening or alteration of the strength of bond between two adhered surfaces.

Embodiments of controlled adhesion of the seal between leading edge 12 and trailing edge 14 of tear strip 11 are shown in the drawings. The first, as shown in FIG. 5 includes herringbone half-scores 31 in the underlying trailing edge 14 of tear strip 11. These halfscores 31 penetrate trailing edge 14 to a depth less than the depth of the paperboard at that point, and therefore do not allow bacteria to penetrate that portion of package 10. When leading edge 12 is lifted from a position of coplanarity with package side 17, the adhesive between leading edge 12 and trailing edge 14 does not yield. Instead, that portion of trailing edge 14 between half-cut scores 31 will rip up and partially delaminate trailing edge 14. As leading edge 12 continues to be pulled away from trailing edge 14, trailing edge 14 continues its delamination along half-scores 31 until the end of trailing edge 14 is reached. At that point, a substantial portion of half-cut trailing edge 14 has pulled away from the package with leading edge 12. Delamination of delamination planes 23 has begun and tear strip is completely intact as it forms an opening around substantially the entire circumference of package 10.

Another form of the weakened seal of package 10 is shown in FIG. 7 and includes ink-printed adhesive areas 40 bounded on all sides thereof by adhesive areas 41. Bust as half-cut scores 31 of FIG. 5 weakened the seal between leading edge 12 and trailing edge 14, so

adhesive ink areas 40 weaken the seal between leading edge 12 and trailing edge 14 in FIG. 7. The major difference between the weakened seal of FIG. 5 and that of FIG. 7 is the location of the weakened point of the sea]. In FIG. 5 the plane of delamination of trailing edge 14 is coplanar with half-cut scores 31. The weakened portion of the seal of FIG. 7, however, is the plane of intersection of the adhesive and the upper printed surface of trailing edge 14. The embodiment of FIG. 6 combines herringbone half-scores 31 with adhesive ink areas 40 to provide yet another form of weakened seal area between leading edge 12 and trailing edge 14.

Thus it can be seen that an improved tear-strip seal for sterile medical packages has been shown. Further modifications and alternative embodiments of th invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and as for the purpose of teaching those skilled in the art the manner of carrying out the invention, it is to be understood that the form of the invention herewith shown anddescribed is to be taken as the presently preferred embodiment. Various changes may be made in the shape, size and arrangement of parts. For example, equivalent elements for materials may be substituted for those illustrated and described herein, parts may be reversed, and certain features of the invention may be utilized independently of the use of other features, all as would be apparent to one skilled in the art, after having the benefit of this description.

What is claimed is:

1. In a bacteria-impermeable seal for an opening tear strip in a sterile material package folded from a sheet of paperboard such that one edge of said sheet overlaps the opposite edge of said sheet and is adhesively attached thereto to form a manufactures seam, and in which said tear strip is integral with said sheet and extends around the circumference of said package and wherein the overlying leading edge of said tear strip is secured to the underlying trailing end of said tear strip in the area of said manufactures seam, the improvement comprising:

a plurality of individually discrete ink printed areas provided on one of the interfacing surfaces of said underlying end and said overlying end of said tear strip such that the printed areas are discontinuous and the non-printed area is continuous;

and a layer of adhesive applied between said interfacing surfaces an over said ink printed areas, whereby said overlying and underlying ends of said tear strip are provided with a weakened bacteriaimpermeable seal with improved opening characteristics.

2. The invention as claimed in claim 1 wherein:

the one of said overlying and underlying ends of said tear strip is provided with a plurality of discrete discontinuous score lines on the interfacing surface thereof.

3. In a bacteria-impermeable seal for an opening tear strip in a sterile material package folded from a sheet of paperboard such that one edge of said sheet overlaps the opposite edge of said sheet and is adhesively attached thereto to form a manufactures seam, and in which said tear strip is integral with said sheet and extends around the circumference of said package and wherein the overlying leading end of said tear strip is secured to the underlying trailing end of said tear strip in the area of said manufactures scam, the improvement comprising:

a plurality of individually discrete ink printed areas provided on the interfacing surface of said underlying end of said tear strip such that the printed areas are discontinuous and the non-printed area is continuous;

a layer of adhesive applied between said interfacing surfaces and over said ink printed areas;

and said underlying end of said tear strip is provided with a plurality of discrete discontinuous score lines on the interfacing surface thereof, whereby said overlying and underlying ends of said tear strip are provided with a weakened bacteriaimpermeable seal with improved opening characteristics.

Patent No. 3,773,

Dated November 20, 1973 HoWard F. Cecil and James L. Armentrout It is certified that error appears in the-above-identified patent" and that said Letters Patent are hereby corrected as 'shown'below:

column 1 line 19, the first listed U.S. Patent No. appears incorrectly and should be --2,626,096-

column 1 line 42; the word --Theappears incorrectly.

column 1 line 54, the word --areas-- should be inserted before the word "completely.

column 2 line 2, "ordinary" should be orderly--.

column 2 line ll, the word --isometrichas been spelled incorrectly. column 2 line 32,

column 3 1ineL|.6., column 3 line 62,

column 4 line 20,

column l line 31,

Signed and sealed (SEAL) Attest:

the

the

the

the

word --andappears incorrectly.

this ll th day of May 1971+.

EDWARD I 'I.FLETGHER, 11. Attesting Officer F ORM PO-IOSO (10-65) C. MARSHALL DAI-IN Commissioner .of Patents 

1. In a bacteria-impermeable seal for an opening tear strip in a sterile material package folded from a sheet of paperboard such that one edge of said sheet overlaps the opposite edge of said sheet and is adhesively attached thereto to form a manufacture''s seam, and in which said tear strip is integral with said sheet and extends around the circumference of said package and wherein the overlying leading edge of said teAr strip is secured to the underlying trailing end of said tear strip in the area of said manufacture''s seam, the improvement comprising: a plurality of individually discrete ink printed areas provided on one of the interfacing surfaces of said underlying end and said overlying end of said tear strip such that the printed areas are discontinuous and the non-printed area is continuous; and a layer of adhesive applied between said interfacing surfaces an over said ink printed areas, whereby said overlying and underlying ends of said tear strip are provided with a weakened bacteria-impermeable seal with improved opening characteristics.
 2. The invention as claimed in claim 1 wherein: the one of said overlying and underlying ends of said tear strip is provided with a plurality of discrete discontinuous score lines on the interfacing surface thereof.
 3. In a bacteria-impermeable seal for an opening tear strip in a sterile material package folded from a sheet of paperboard such that one edge of said sheet overlaps the opposite edge of said sheet and is adhesively attached thereto to form a manufacture''s seam, and in which said tear strip is integral with said sheet and extends around the circumference of said package and wherein the overlying leading end of said tear strip is secured to the underlying trailing end of said tear strip in the area of said manufacture''s seam, the improvement comprising: a plurality of individually discrete ink printed areas provided on the interfacing surface of said underlying end of said tear strip such that the printed areas are discontinuous and the non-printed area is continuous; a layer of adhesive applied between said interfacing surfaces and over said ink printed areas; and said underlying end of said tear strip is provided with a plurality of discrete discontinuous score lines on the interfacing surface thereof, whereby said overlying and underlying ends of said tear strip are provided with a weakened bacteria-impermeable seal with improved opening characteristics. 